Hyperlipidemia is a major risk factor in the development of arteriosclerosis. Understanding the pathogenesis of hyperlipidemia would help in the development of prevention and or treatment of arteriosclerosis. It is proposed to develop experimental animal models or hyperlipidemia to study the mechanism of its development. Apoproteins are major constituents of lipoproteins and play an important role in the metabolism of lipoproteins: studies are directed to elucidate the physiology of apolipoproteins and their role in hyperlipidemia. It is planned to characterize hyperlipidemia according to alterations in apolipoprotein profile which could be an index for differentiating the different types of hyperlipidemia.